Safety device for incandescent lamps



(No Model.)

' E. A. SPERRY.

SAFETY DEVICE POR INGANBBSGBNT LAM-Ps. No.'361,8443 Patented Apr. 26,1887.

@INH

N. PETERS, Phulo-lilhugmphcr, wnnhingtun. D. C.

UNITED STATES PATENT CEEICE.

ELMER A. SPERRY, OF CHICAGO, ILLINOIS.` g

SAFETY DEVICE FOR INCANDESCENT LAMPS.

SPECIFICATION forming part of Letters Patent No. 361,844, dated April 26, 1887.

Application lcd May 22, 1856.

To all whom, it mag/concern,.-

Beit known that I, ELMER A. SPEERY, acitizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Safety Devices for Incandescent Lamps, of which the following is a specification.

My invention has for its object to provide means for throwing into action by automatic devices a resistance lamp or filament when the light-giving lamp is destroyed or thrown out ofaetion, and for completing the line-circuit when all the lamps or filaments of a given series are exhausted, so that the operation of other vlamps in the same system shall not be interrupted.

I accomplish the desired result by means of a resistance-lamp, which is mounted on the same support or shell as the light-giving lamp, andit consistsor" an exhausted chamber containing an incandescing filament of greater resistance than the ordinary light-giving lament arranged in a separatevacuum globe or cham'- ber. The arrangement of circuits is such that normally the current passes through an electromagnet, attracts an armature, and passes through the light-giving filament. Vhen the latter is destroyed or switched ont of action, the electro-magnet is demagnetized, the armature drops, and then the current passes through the resistance-lamp, preserves the continuity of the circuit, and protects the other lamps in the same system from being inj uriously affected by an excess of current.

The invention, brieiiy outlined in the above statement, will be more fully hereinafter described, and then set forth in the claims.

In the drawings, Figure 1 is a vertical sec- ,tional view representing the shell or holder,

the resistance-lamp, the electro-magnet, and automatic, switch devices and the ordinary glow 0r illuminating lamp mounted on the same holder. Fig. 2 is a cross-section of the shell or holder and bottom view of the magnetswitch armature and contact or stop device. Fig. 3 is a variation representing a manualswitch device for the light-giving lamp arranged in the shell or holder of the resistancelamp. Fig. 4 is a detail` and diagrammatic view of another form of electro-magnet and balanced armature or automatic switch device.

Serial No. 203,030. (No model.)

The reference-numeral 1 designates a shell or casing, which isgenerally made in the form of a cylinder, and is constructed of metal or other material. The ends of the shell or casing are closed by means of screw-caps 2 and 3, whichA are screwed onto exterior threads on the ends of the cylinder or shell, as is clearly seen in Fig. 1. In this figure one of the end heads is shown provided with a screw neck or 6o nipple, 3, for the reception of the holder 4 of an ordinary incandescing or glow lamp, 5, said nipple being made hollow for the passage of the leading-in wires. The cap 2 also is provided with a screw-socket, 2, for attaching 65 all the devices carried by the shell or casing 1 to a suitable support, bracket, or chandelier. The shell or casing 1 incloses a so-called resistance-lamp, an electro-magnet, automatic switch, and the necessary circuit-wires and 7o' contact devices.

The resistance -lamp is not designed for light-giving purposes, but it is in many respects like an ordnary incandescing lamp, since it comprises an exhausted shell or chamber, 6, an incandescing lament, 7, arranged inside the same, and other details hereinafter mentioned.

The globe or chamber 6 is made of castglass or other vitreous material, and is formed 8o with a hollow core, 6, forming a continuous passage from end to end of said shell or chamber 6. The filament within said chamber may be termed the resistingtilament,7 to distinguish it from the light-giving filament in the incandescing or illuminating lamp. rIhe resistances of these two filaments are so proportioned that the resisting-filament offers to the current or electric-motive force a resistance, when at a dull-red heat, or thereabout, which 9o is equal to the hot resistance of theincandescing-lamp or light-giving filament. By the expression hot resistance is meant the resistance when the filament is at the normal degree of ineandescence.

Beneath the end cap, 2, is placed a ring or disk, S, of vulcanized fiber or otherinsulating material, and a small metal annular plate, 9, secured to said disk 8, makes contact with a similar annular plate, 10, held by an annular 1o( shoulder, 63, on the glass shell 6. Metalwires 15, connected with the terminals of the spiral resistingfilament, are sealed in the ends of the shell 6 and connected with the plate 10 and with another similar plate, 11, at the opposite end of the shell 6. Around the exterior of the shell 6 is applied a circumferential sleeve, 12,

of asbestus paper or similar material for pre venting the resistance lamp from touching the exterior metal shell or casing, and to hold it firmlyin position by friction of the sleeve upon the exterior shell.

An electro magnet, 20, bearing other devices, hereinafter referred to, also occupies the interior of the casing 1 and abuts against the resistance-lamp, and after the latter and the electro-magnet have been inserted into the shell 1 a mass of fiber or other semi-elastic rnaterial (designated by the numeral 21) is introduced into the space between the magnet and the end head, 3. It is understood that this material or packing is placed at the sides of or around the armature 24, so as not to interfere with themovement of the latter. The object of this material 21 is to hold the resistancelainp, electro-magnet, and other parts in position and guard against their displacement during transportation and use.

rIhe electromagnet shown in Figs. 1 and 3 consists of the iron core piece 22 and the right-angled iron limb 23, which is connected with said core, and one end arranged to serve as the pole-piece for an armature, 24; This armature is a bar hung at its middle upon the core-pieces 22 by iitting the reduced middle of said bar in the i'urcated end of the core-piece and passing a fulcrum pin, 25, through the core-piece and armature. To one end of the centrally pivoted or balanced armature is at tached a coiled spring, 27, which is also connected with the portion of the limb 23 to which the core-piece is riveted or otherwise fastened. The other end of the armature moves between the pole-face and the metal stop and contactplate 28, which, as is seen in Fig.- 2, is a V- shaped body secured to one of the insulating end heads, 29, of the electro-magnet.

The core-piece is wound with insulated wire to form a bobbin or helix, 30, and the inner and outer terminals of said helix are connected, respectively, withlthe wire 31, coming from the electric main, and the wire 32, extending to one of the leading-wires ofthe light giving or ordinary incandescinglamp. The other leading-in wire of said lamp is connected with the wire 33, which passes through the shell l, and is, together with the wire 31, carried through the hollow center of the resistance-lamp. It is obvious that with the electric conductors thus arranged and the ordinary switch on the incandescing lamp shown in Fig. 1 set to close the circuit, the current will pass through the helix of the electro-magnet and cause an attraction of the armature 24 against the pull of the spring 27, holding the parts in such position. until the circuit is broken by the burning out of the incandescing lamp or the breaking of the circuit by the lamp-switch. Vhen such a result from either of the causes mentioned takes place, the resistance-lamp is thrown into action,and the current will then pass through the wire 31, branch wire 38 connecting the same with the'metal contact 9 on the insulating-disk 8, contact 10, resisting filament, contact 11, contact 40 on the magnet, through the metal core of the latter to the contact 28, and from thence by the branch wire 4l to the conducting-wire 33.

In Fig. 1 the parts are shown in the position they assume whenthe incandescing lamp is cut out of circuit and the resistance-lamp is in action.

1n Fig. 3 I have shown au arrangement of parts in which the switch device for controlling the'incandescing or illuminating lamp is arranged within the shell or holder of the incandescing lamp, the operation of the automatic or armature switch being, however, the same as in the construction shown in Fig. 1. In this variation of my invention the end cap, 3, of the shell 1 is formed with a socket, 3, for the reception of the neck ofan incandescing lamp,and this neck has an annular end plate, 45, of metal, which makes-contact with a similar plate, 46, on an insulating-disk, 47. One of the leading-in wires of thelamp is connected with the plate 45, and the other wire is connected with a metal contact, 48, on a boss, 49, on the lamp. A plate, 50, riveted to the insulated disk 47, bears on the contact48, and in co-operativc relation to said plate is arranged a pivoted tongue, 5,2, which is in metallic connection with the helix of the electro-magnet. The tongue 52 is held away from plate 50 by the action of a spring, 53, and it is depressed upon said plate by means of an eccentric, 54, on a shaft or arbor, 55, passing through the shell 1, and having a head for manipulating the same. The metal plate 46 on the insulating-disk 47 is connected by a branch wire, 56, with the contact device 28, and the main conductingwire is also connected with said plate 46, s0 as to complete the circuit through the incandescing lamp when the spring-tongue is depressed by vthe eccentric upon the contactplate 4S. When the parts are in the position shown in Fig. 3, the circuit is through the resistancelarnp, and the balanced armature is firmly held upon the contact-plate 28 by the pressure of the eccentric upon the springbearing end of the armature.

In the diagram, Fig. 4, I have shown au electromagnet of a peculiar form; but the principle of the balanced or centrally-pivoted armature is also preserved in this instance, with the difference that the armature is attracted and held by two pole-faces. The electrical connections are also varied, and may be traced for the incandescing lamp through the wire 31, switch 60, lamp 69,wire 61, helix 62, wire 63, helix 64, wire 65, and main wire 33.

For the resistance lamp the current is through wire 31, resisting filan1ent-core of magnet 62, contact 66, and wire 33. The two helices shown in Fig. 4, ,together with their cores, constituting north and south poles, are attached to oblique top and bottom bars, 68, of metal, and the armature is hung upon said bars by a pivotpin, so as to have its ends act upon the two polefaces, as is seen in Fig. 4. When the magnet is demagnetized, the armature will assume a position midway between the two helices and remain perfectly balanced, so as to respond quickly to the magnets action.

It should be observed, in reference to the switching out of the incandescing lamp employed in connection with the safety device seen in Fig. 3, that in order to prevent sparking between the pivoted tongue 52 and contactplate 48 the relation between the eccentric 54 and the contact between the armature 24 and plate 28 should be such that the contact between the parts 24 and 28 is established and the resistance-lamp put into circuit before the circuit in the incandescing illuminating-filament is broken by the separation of the tongue 52 and plate 48. By preserving the above relations and operating in the describedmanner a spark is not formed between the parts 52 and 48.

1. The combination,with an ordinary7 incandescent light-giving lamp and electric-circuit wires,o` an incandescing resistance-lamp cornprising an exhausted globe or chamber, a filament offering a greater resistance to the elec tric current than the Alightgiving lament, a holder for supporting both lamps, and means. substantially'as described, mounted upon said holder for establishing electrical communication from one lamp to the other, as and for the object stated.

2. The combination,with an ordinary incandescing illuminating-lamp, of an incandescing resistance-lamp arranged in electrical connection or circuit with said illuminating-lamp, and provided with a filament of larger ampre capacity than the light-giving filament, substantially as herein set forth.

. 3. The combination of the resistance-lamp, comprising an exhausted shell orflask having a hollow core and inclosing an Iincandescing lament, wit-h an inclosing case or'shell, electrical conductors, an incandescing illuminating-lamp, and means for diverting the electric current from the latter lamp through the resistance-lamp,substantially as herein set forth.

4. The combination of the shell or holder having detachable end heads, the resistancelarnp, electro-magnet, and switch devices inclosed within said holder, the ordinary incandescing lamp connected with the holder, and electrical conductors, substantially as herein set forth.

5. The combination,with an exposed incan' descing illuminating-lamp, of a hollow holder or supporting-case for the same, an incandescing resistancelamp, an electro-magnet, and an automatic switch arranged or inclosed within said holder or case, and circuit wires and connections for passing the current either through the helix of the electro-magnet and illuminatinglamp or through the resistancelamp, substantially as described.

6. The combination of the incandescent resistance-lamp, the electro-magnet, the centrally-'pivoted balanced armature, the spring acting upon said armature when not attracted by the magnet, and the contact device, upon which the armature rests when the magnet is demagnetized, with the holder inclosing the parts above mentioned, the ordinary incandescing lamp attached to the same holder,and circuit-connections, substantially as herein set -forth.

7. rlhe combination,with incandescing illuminating and resistance lamps, and a holder common to both 1amps,of an automatic switch for sending the electric current through one or the'other of said lamps under the conditions specified, and a manual-switch device consisting of an eccentric, spring, tongue, contact devices, and electrical conductors, substantially as herein set forth.

8. The combination` with an incandescing lamp and aresistance-filamentin an exhausted flask contained or supported by the same holder, and an automatic switch mechanism to throw the current from one to the other, of a manual-switch device operating to connect the circuit to the resistanceiilament just before it breaks connection with the incandescing filament, substantially as and for the purpose specified.

In testimony whereof I affix my signature in presence of two witnesses.

ELMER A. SPERRY.

VitnesseS:

J oHN E. BURKE, LYMAN EVERINGHAM.

IOO 

